It is known, for example, that the exhalation or emission of water vapor from the surface of green tissues in living plants facilitates the absorption of aqueous nutrients by the roots and additionally promotes necessary gaseous interchange between plant tissues and the external air. However, in semi-arid geographic regions, maximum crop production is limited by a combination of the cost and availability of irrigation water and the water-use efficiency of the particular varieties of agricultural plants being grown. As a consequence, the modern phenomena of diminished water supplies and rising energy costs required to pump irrigation water have lead to the commercial introduction of antitranspirant materials based on emulsified waxes and polyolefins. These compositions have proved capable of decreasing plant transpiration; but care must be exercised in their use both to prevent phytotoxicity, as exhibited for example by leaf burn, and to avoid actual diminution in crop yields.